Recent years have seen an increase in public awareness and concern over environmental issues, particularly the prospect of global warming resulting from the so-called greenhouse effect. This effect results from an increased concentration of carbon dioxide and other gases in the earth's atmosphere, which causes increased retention of heat energy in the lower regions of the earth's atmosphere. This effect is caused not only by the burning of increased amounts of fossil fuels but also by the high rate of deforestation in many parts of the world, since trees and other plants are important for absorbing atmospheric carbon dioxide and converting it into oxygen.
Accordingly, there is a need to counteract these detrimental effects if the earth's environment is to be preserved. One of the ways this may be done is by increasing the population of trees or other plants, thereby providing a replenished means for carbon dioxide absorption from the atmosphere, as well as contributing to the health of the environment by reducing pollution and soil erosion and replenishing wildlife habitat.
Preferably this increase of tree and plant population should be widespread and on an overall large scale if it is to be effective. Therefore, it would be desirable to provide means for cultivating and growing trees or other plants, which may be conveniently distributed in large numbers over a wide area to a large number of individuals, each of whom could thus participate in the effort to reduce the detrimental greenhouse effect.